Commit 35df3b29 authored by Antonio Quartulli's avatar Antonio Quartulli Committed by Antonio Quartulli

batman-adv: fix TT VLAN inconsistency on VLAN re-add

When a VLAN interface (on top of batX) is removed and
re-added within a short timeframe TT does not have enough
time to properly cleanup. This creates an internal TT state
mismatch as the newly created softif_vlan will be
initialized from scratch with a TT client count of zero
(even if TT entries for this VLAN still exist). The
resulting TT messages are bogus due to the counter / tt
client listing mismatch, thus creating inconsistencies on
every node in the network

To fix this issue destroy_vlan() has to not free the VLAN
object immediately but it has to be kept alive until all the
TT entries for this VLAN have been removed. destroy_vlan()
still removes the sysfs folder so that the user has the
feeling that everything went fine.

If the same VLAN is re-added before the old object is free'd,
then the latter is resurrected and re-used.

Implement such behaviour by increasing the reference counter
of a softif_vlan object every time a new local TT entry for
such VLAN is created and remove the object from the list
only when all the TT entries have been destroyed.
Signed-off-by: default avatarAntonio Quartulli <antonio@open-mesh.com>
Signed-off-by: default avatarMarek Lindner <mareklindner@neomailbox.ch>
parent d46b6bfa
...@@ -448,10 +448,15 @@ void batadv_interface_rx(struct net_device *soft_iface, ...@@ -448,10 +448,15 @@ void batadv_interface_rx(struct net_device *soft_iface,
* possibly free it * possibly free it
* @softif_vlan: the vlan object to release * @softif_vlan: the vlan object to release
*/ */
void batadv_softif_vlan_free_ref(struct batadv_softif_vlan *softif_vlan) void batadv_softif_vlan_free_ref(struct batadv_softif_vlan *vlan)
{ {
if (atomic_dec_and_test(&softif_vlan->refcount)) if (atomic_dec_and_test(&vlan->refcount)) {
kfree_rcu(softif_vlan, rcu); spin_lock_bh(&vlan->bat_priv->softif_vlan_list_lock);
hlist_del_rcu(&vlan->list);
spin_unlock_bh(&vlan->bat_priv->softif_vlan_list_lock);
kfree_rcu(vlan, rcu);
}
} }
/** /**
...@@ -505,6 +510,7 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid) ...@@ -505,6 +510,7 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
if (!vlan) if (!vlan)
return -ENOMEM; return -ENOMEM;
vlan->bat_priv = bat_priv;
vlan->vid = vid; vlan->vid = vid;
atomic_set(&vlan->refcount, 1); atomic_set(&vlan->refcount, 1);
...@@ -516,6 +522,10 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid) ...@@ -516,6 +522,10 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
return err; return err;
} }
spin_lock_bh(&bat_priv->softif_vlan_list_lock);
hlist_add_head_rcu(&vlan->list, &bat_priv->softif_vlan_list);
spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
/* add a new TT local entry. This one will be marked with the NOPURGE /* add a new TT local entry. This one will be marked with the NOPURGE
* flag * flag
*/ */
...@@ -523,10 +533,6 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid) ...@@ -523,10 +533,6 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
bat_priv->soft_iface->dev_addr, vid, bat_priv->soft_iface->dev_addr, vid,
BATADV_NULL_IFINDEX, BATADV_NO_MARK); BATADV_NULL_IFINDEX, BATADV_NO_MARK);
spin_lock_bh(&bat_priv->softif_vlan_list_lock);
hlist_add_head_rcu(&vlan->list, &bat_priv->softif_vlan_list);
spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
return 0; return 0;
} }
...@@ -538,18 +544,13 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid) ...@@ -538,18 +544,13 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
static void batadv_softif_destroy_vlan(struct batadv_priv *bat_priv, static void batadv_softif_destroy_vlan(struct batadv_priv *bat_priv,
struct batadv_softif_vlan *vlan) struct batadv_softif_vlan *vlan)
{ {
spin_lock_bh(&bat_priv->softif_vlan_list_lock);
hlist_del_rcu(&vlan->list);
spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
batadv_sysfs_del_vlan(bat_priv, vlan);
/* explicitly remove the associated TT local entry because it is marked /* explicitly remove the associated TT local entry because it is marked
* with the NOPURGE flag * with the NOPURGE flag
*/ */
batadv_tt_local_remove(bat_priv, bat_priv->soft_iface->dev_addr, batadv_tt_local_remove(bat_priv, bat_priv->soft_iface->dev_addr,
vlan->vid, "vlan interface destroyed", false); vlan->vid, "vlan interface destroyed", false);
batadv_sysfs_del_vlan(bat_priv, vlan);
batadv_softif_vlan_free_ref(vlan); batadv_softif_vlan_free_ref(vlan);
} }
...@@ -567,6 +568,8 @@ static int batadv_interface_add_vid(struct net_device *dev, __be16 proto, ...@@ -567,6 +568,8 @@ static int batadv_interface_add_vid(struct net_device *dev, __be16 proto,
unsigned short vid) unsigned short vid)
{ {
struct batadv_priv *bat_priv = netdev_priv(dev); struct batadv_priv *bat_priv = netdev_priv(dev);
struct batadv_softif_vlan *vlan;
int ret;
/* only 802.1Q vlans are supported. /* only 802.1Q vlans are supported.
* batman-adv does not know how to handle other types * batman-adv does not know how to handle other types
...@@ -576,7 +579,36 @@ static int batadv_interface_add_vid(struct net_device *dev, __be16 proto, ...@@ -576,7 +579,36 @@ static int batadv_interface_add_vid(struct net_device *dev, __be16 proto,
vid |= BATADV_VLAN_HAS_TAG; vid |= BATADV_VLAN_HAS_TAG;
/* if a new vlan is getting created and it already exists, it means that
* it was not deleted yet. batadv_softif_vlan_get() increases the
* refcount in order to revive the object.
*
* if it does not exist then create it.
*/
vlan = batadv_softif_vlan_get(bat_priv, vid);
if (!vlan)
return batadv_softif_create_vlan(bat_priv, vid); return batadv_softif_create_vlan(bat_priv, vid);
/* recreate the sysfs object if it was already destroyed (and it should
* be since we received a kill_vid() for this vlan
*/
if (!vlan->kobj) {
ret = batadv_sysfs_add_vlan(bat_priv->soft_iface, vlan);
if (ret) {
batadv_softif_vlan_free_ref(vlan);
return ret;
}
}
/* add a new TT local entry. This one will be marked with the NOPURGE
* flag. This must be added again, even if the vlan object already
* exists, because the entry was deleted by kill_vid()
*/
batadv_tt_local_add(bat_priv->soft_iface,
bat_priv->soft_iface->dev_addr, vid,
BATADV_NULL_IFINDEX, BATADV_NO_MARK);
return 0;
} }
/** /**
......
...@@ -511,6 +511,7 @@ bool batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr, ...@@ -511,6 +511,7 @@ bool batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr,
struct batadv_priv *bat_priv = netdev_priv(soft_iface); struct batadv_priv *bat_priv = netdev_priv(soft_iface);
struct batadv_tt_local_entry *tt_local; struct batadv_tt_local_entry *tt_local;
struct batadv_tt_global_entry *tt_global = NULL; struct batadv_tt_global_entry *tt_global = NULL;
struct batadv_softif_vlan *vlan;
struct net_device *in_dev = NULL; struct net_device *in_dev = NULL;
struct hlist_head *head; struct hlist_head *head;
struct batadv_tt_orig_list_entry *orig_entry; struct batadv_tt_orig_list_entry *orig_entry;
...@@ -572,6 +573,9 @@ bool batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr, ...@@ -572,6 +573,9 @@ bool batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr,
if (!tt_local) if (!tt_local)
goto out; goto out;
/* increase the refcounter of the related vlan */
vlan = batadv_softif_vlan_get(bat_priv, vid);
batadv_dbg(BATADV_DBG_TT, bat_priv, batadv_dbg(BATADV_DBG_TT, bat_priv,
"Creating new local tt entry: %pM (vid: %d, ttvn: %d)\n", "Creating new local tt entry: %pM (vid: %d, ttvn: %d)\n",
addr, BATADV_PRINT_VID(vid), addr, BATADV_PRINT_VID(vid),
...@@ -604,6 +608,7 @@ bool batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr, ...@@ -604,6 +608,7 @@ bool batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr,
if (unlikely(hash_added != 0)) { if (unlikely(hash_added != 0)) {
/* remove the reference for the hash */ /* remove the reference for the hash */
batadv_tt_local_entry_free_ref(tt_local); batadv_tt_local_entry_free_ref(tt_local);
batadv_softif_vlan_free_ref(vlan);
goto out; goto out;
} }
...@@ -1009,6 +1014,7 @@ uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv, ...@@ -1009,6 +1014,7 @@ uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv,
{ {
struct batadv_tt_local_entry *tt_local_entry; struct batadv_tt_local_entry *tt_local_entry;
uint16_t flags, curr_flags = BATADV_NO_FLAGS; uint16_t flags, curr_flags = BATADV_NO_FLAGS;
struct batadv_softif_vlan *vlan;
tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr, vid); tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr, vid);
if (!tt_local_entry) if (!tt_local_entry)
...@@ -1039,6 +1045,11 @@ uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv, ...@@ -1039,6 +1045,11 @@ uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv,
hlist_del_rcu(&tt_local_entry->common.hash_entry); hlist_del_rcu(&tt_local_entry->common.hash_entry);
batadv_tt_local_entry_free_ref(tt_local_entry); batadv_tt_local_entry_free_ref(tt_local_entry);
/* decrease the reference held for this vlan */
vlan = batadv_softif_vlan_get(bat_priv, vid);
batadv_softif_vlan_free_ref(vlan);
batadv_softif_vlan_free_ref(vlan);
out: out:
if (tt_local_entry) if (tt_local_entry)
batadv_tt_local_entry_free_ref(tt_local_entry); batadv_tt_local_entry_free_ref(tt_local_entry);
...@@ -1111,6 +1122,7 @@ static void batadv_tt_local_table_free(struct batadv_priv *bat_priv) ...@@ -1111,6 +1122,7 @@ static void batadv_tt_local_table_free(struct batadv_priv *bat_priv)
spinlock_t *list_lock; /* protects write access to the hash lists */ spinlock_t *list_lock; /* protects write access to the hash lists */
struct batadv_tt_common_entry *tt_common_entry; struct batadv_tt_common_entry *tt_common_entry;
struct batadv_tt_local_entry *tt_local; struct batadv_tt_local_entry *tt_local;
struct batadv_softif_vlan *vlan;
struct hlist_node *node_tmp; struct hlist_node *node_tmp;
struct hlist_head *head; struct hlist_head *head;
uint32_t i; uint32_t i;
...@@ -1131,6 +1143,13 @@ static void batadv_tt_local_table_free(struct batadv_priv *bat_priv) ...@@ -1131,6 +1143,13 @@ static void batadv_tt_local_table_free(struct batadv_priv *bat_priv)
tt_local = container_of(tt_common_entry, tt_local = container_of(tt_common_entry,
struct batadv_tt_local_entry, struct batadv_tt_local_entry,
common); common);
/* decrease the reference held for this vlan */
vlan = batadv_softif_vlan_get(bat_priv,
tt_common_entry->vid);
batadv_softif_vlan_free_ref(vlan);
batadv_softif_vlan_free_ref(vlan);
batadv_tt_local_entry_free_ref(tt_local); batadv_tt_local_entry_free_ref(tt_local);
} }
spin_unlock_bh(list_lock); spin_unlock_bh(list_lock);
...@@ -3139,6 +3158,7 @@ static void batadv_tt_local_purge_pending_clients(struct batadv_priv *bat_priv) ...@@ -3139,6 +3158,7 @@ static void batadv_tt_local_purge_pending_clients(struct batadv_priv *bat_priv)
struct batadv_hashtable *hash = bat_priv->tt.local_hash; struct batadv_hashtable *hash = bat_priv->tt.local_hash;
struct batadv_tt_common_entry *tt_common; struct batadv_tt_common_entry *tt_common;
struct batadv_tt_local_entry *tt_local; struct batadv_tt_local_entry *tt_local;
struct batadv_softif_vlan *vlan;
struct hlist_node *node_tmp; struct hlist_node *node_tmp;
struct hlist_head *head; struct hlist_head *head;
spinlock_t *list_lock; /* protects write access to the hash lists */ spinlock_t *list_lock; /* protects write access to the hash lists */
...@@ -3167,6 +3187,12 @@ static void batadv_tt_local_purge_pending_clients(struct batadv_priv *bat_priv) ...@@ -3167,6 +3187,12 @@ static void batadv_tt_local_purge_pending_clients(struct batadv_priv *bat_priv)
tt_local = container_of(tt_common, tt_local = container_of(tt_common,
struct batadv_tt_local_entry, struct batadv_tt_local_entry,
common); common);
/* decrease the reference held for this vlan */
vlan = batadv_softif_vlan_get(bat_priv, tt_common->vid);
batadv_softif_vlan_free_ref(vlan);
batadv_softif_vlan_free_ref(vlan);
batadv_tt_local_entry_free_ref(tt_local); batadv_tt_local_entry_free_ref(tt_local);
} }
spin_unlock_bh(list_lock); spin_unlock_bh(list_lock);
......
...@@ -687,6 +687,7 @@ struct batadv_priv_nc { ...@@ -687,6 +687,7 @@ struct batadv_priv_nc {
/** /**
* struct batadv_softif_vlan - per VLAN attributes set * struct batadv_softif_vlan - per VLAN attributes set
* @bat_priv: pointer to the mesh object
* @vid: VLAN identifier * @vid: VLAN identifier
* @kobj: kobject for sysfs vlan subdirectory * @kobj: kobject for sysfs vlan subdirectory
* @ap_isolation: AP isolation state * @ap_isolation: AP isolation state
...@@ -696,6 +697,7 @@ struct batadv_priv_nc { ...@@ -696,6 +697,7 @@ struct batadv_priv_nc {
* @rcu: struct used for freeing in a RCU-safe manner * @rcu: struct used for freeing in a RCU-safe manner
*/ */
struct batadv_softif_vlan { struct batadv_softif_vlan {
struct batadv_priv *bat_priv;
unsigned short vid; unsigned short vid;
struct kobject *kobj; struct kobject *kobj;
atomic_t ap_isolation; /* boolean */ atomic_t ap_isolation; /* boolean */
......
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